1. Field of the Invention
The present invention concerns a method for premixed combustion. It also concerns a burner for carrying out the method.
2. Discussion of Background
A burner is known from EP-A1-0321 809 in whose internal space is placed a fuel nozzle from which a cone-shaped column of fuel forms spreading cut in the flow direction, the column being mixed by a rotating combustion airflow flowing tangentially into the burner, which consists of two hollow partial conical bodies positioned one upon the other with increasing conical opening in the flow direction and with centrelines offset relative to one another. The ignition of the air/fuel mixture takes place at the outlet from the burner, a "reverse flow zone", which prevents flashback of the flame from the combustion space into the burner, forming in the region of the burner mouth.
If diesel oil is used as fuel in a combustion chamber with a high pressure ratio, it has been found that it can ignite, at high pressure ratios, immediately after mixture formation in the burner. For this reason, premixed operation at high pressure ratios cannot always be achieved in the case of liquid fuel. The reason for the great differences in terms of ignition delay period is associated with the flame radiation At high pressures, the flame radiation (H.sub.2 O, CO) will be very high; a substantial part of the radiation is absorbed by the fuel droplets (opaque mist). This energy transfer mechanism to the liquid fuel leads to a drastic reduction in the ignition delay period.